1.) Field of the Invention
The invention relates to a cross-strut arrangement for a folding roller-mounted chair having at least two struts connected in a crosswise manner via a cross-strut articulation and designed such that they can be changed in length, telescopically, to adjust the seat width. At the top end of each strut a seat is mounted in the longitudinal direction of the folding roller-mounted chair transverse to the strut for fixing the seat surface and which is adjustable to increase the seat depth.
2.) Description of the Related Art
U.S. Pat. No. 4,989,890 disclosed that two struts are changed in length to change the seat width, that is, to widen the frame of the roller-mounted chair, by telescopically adjusting the struts on each side. The '890 design, however, limits the maximum length adjustment. Moreover, the large number of components renders the design somewhat unstable and is comparatively expensive to produce because of the large number of structural elements and assembly connections.
To increase the seat depth, in this previously known design, each seat profile is provided with a front extension piece, which can be fitted onto the tubular seat profile if necessary. This solution appears to be disadvantageous because if an increased seat depth is required, then, not only must the extension pieces be utilized, but a longer seat cover must be used which must be specially refitted for the seat user.